//说明EventEmitter的用法

//相当于导入库？
var EventEmitter = require('events').EventEmitter;

var event = new EventEmitter();

event.on('some_event',
    function () {
        console.log('some_event occured..');
    }
);

setTimeout(function () {
    event.emit('some_event');
}, 2000);  

//2秒后控制台输出文本
